High-performance butyl rubber tape, designed for joining membranes to create a superior barrier against methane and radon gases. This double-sided tape is ideal for use with damp proof membranes, radon, and methane gas barriers. With excellent elongation properties and a very low moisture vapour transmission rate, it provides a long-lasting solution that matches the lifetime of the building. Perfect for mating gas barriers and plastic sheeting, and can be used as an alternative to welding.